Abstract In the United States, 25.8 million children and adults have diabetes and 79 million have pre-diabetes. Insulin therapy is critical in Type 1 Diabetes and now understood to be an inevitable therapeutic component for Type 2 Diabetes in order to achieve adequate glycemic control. However, none of the available commercial insulin preparations are able to simulate normal secretion and current glucose monitoring and insulin delivery devices struggle to maintain euglycemia during periods of meal and alcohol consumption and during exercise because they cannot fully account insulin absorption variability. This results in unpredictable blood glucose excursions and risk of hypoglycemia due to insulin stacking. Adapting insulin therapy based on personal measures of insulin pharmacokinetics can overcome this limitation, however, since insulin currently must be measured in a lab facility, extending these benefits to the 6 million individuals using insulin therapy is not possible. Thus, there is critical unmet need for a personal device that measures insulin on the spot. To address this need we developed a novel aptamer-based device, the INSIGHT Insulin Sensor, which measures the concentration of insulin on the spot in real time in an episodic manner and supports compatibility with the established glucose motioning technologies. In this Phase II work, Aptitude will collaborate with researchers at Yale School of Medicine, to translate the proof of concept device developed in Phase I into a manufacture-ready prototype that is deployable in research labs and in clinical research settings. Our team will compare the device to the current standard lab- based assay and measure personal insulin pharmacokinetics in patients, and assess the capability to improve insulin pumps. Through measures of personal insulin pharmacokinetics, INSIGHT has the potential to augment existing insulin delivery devices to improve glucose control during challenging real-life scenarios, and will support proliferation of artificial pancreas systems through safer and more effective glucose control. We expect to form a product co-development partnership with leaders in the diabetes device market for commercialization within three years.